Synchronizer.



Nb. 843,266. PATENTED PEB. 5, 1907.

` w. H. FREBDMANI SYNCHRONIZER.

APPLIOA TION FILED JUNE 13, 1903.

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SYNCHRONIZEIL APPLICATION FILED JUNI: 13-, 1903.

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SYNCHRONIZER.

Specification of Letters Patent.

Patented Feb. 5, 1907'.

Application filed Juno 13, 1903. Serial No. 161.279.

To @ZZ whom t may concern:

Be it known that l, WILLIAM Hona'rio FREEDMAN, a citizen of the United States of America, and a resident of Burlington, in the county of Chittenden and State of Vermont, have invented certain new and useful lmprovements in Synchronizers, of which the following is a specification.

My invention relates to an apparatus for synchronizing polyphase or single-phase circuits, my object being in particular to provide a synchronizing instrument by which two polyphase or single-phase generators may be quickly and readily brought into concordance before coupling them in parallel or by which any polyphase or single-phase generator may be broughtI into synchronism with the line-circuit before throwing it upon the line.

Another obj ect of my inventionis to provide the instrument with means whereby it may also be used as an instrument to indicate lag or lead of the current in any circuit and the power factor of that circuit-that is 'to say, to indicate, generally, the angle at which the current in the circuit lags behind or leads in advance of the pressure curve-and also the power factor itself, which is proportionate to the cosine of said angle.

My invention comprises in its elements, first, a rotating magnetic field, the part producing which is held stationary, and, secondly, a rotating or alternating tield which is adapted to turn relatively to the first, or vice versa, these two members being connected up in pressure relation respectively to the two generators which are to be coupled in parallel or to the generator and the linecircuit, as the case may be, the arrangement being such that the movable member is stationary when the two generators are at the saine frequency and at any other time the movablemember rotates with respect to the stationary member at a greater or less speed in one direction or the other according as one of the generators is giving a frequency greater or less 'than that of the other.

My invention also comprises means for changing the connections of the instrument, whereby one of the members is connected in series with any generator and the other in parallel or pressure relation therewith, whereby in this case the movable member will take up a certain position with relation to the other at a varying angle, depending upon the lag or lead of the current in the generator-circuit and, further, in providing means, such as a pointer and scale, for determining such position, and hence the angle of lag or lead. In either case one of the members only need have a rotating field and the other need only have an alternating field of the same l'requency, and either member may be made rotatable and the other stationary.

In the drawings accompanying this specification I have illustrated the several embodiments of my invention for two and tln'ee phase circuits, and herein- Figure l is a vertical central section, and Fig. 2 is a plan, of a synchronizer adapted for use with a three-phase circuit. Fig. 3 is a plan view of the saine with the cover removed. Fig. 4 is a central vertical section of a modified forni of instrument adapted for two or three phase circuits. Fig. 5 is a central vertical section of another niodilied form. Fig. 6 is a section of the saine on the line 6 6 of Fig. 5. Figs. 7 and S are respectively a central vertical section and a plan of a third forni of instruirtent. Fig. 9 is a plan view of a colnbination synchronizer and phase-lag indicator. Fig. 10 shows a side elevation of a switchboard instrument adapted for side reading. Fig. 1l is a diagralnmatic view showing the connections of a double-ring instrunent for coupling two twophase generators in parallel. Fig. 12 shows the arrangement 'for coupling a two-phase generator to a line-circuit. Fig. 13 is a diagraln of connection for synchronizing any one of a series of three-phase generators with the line. Fig. 14 is a diagram of connections for a combined synclu'onizer and phase-lag indicator for a three phase circuit or a combined synchronizer and power-factor indicator for a three-phase circuit. Fig. 15 shows the connections for synchronizing any one of a series of two-phase generators with a line, the synchronizer being of the form shown in Fig. 4. Fig. i6 is a similar diagrau for a three-phase circuit.

In the instrument shown in Fig. l, 20 and 2l represent `two circular or ring coils, each comprising a core of iron wire 22 23 and insulated coinluctor-wire 2-1 25 wound thereover in the same manner as in the Gramme ring. These coils are shown one within the other and in the closest possible magnetic relation. It will be understood that the constructions maybe varied by having individual poles on the iron core, if desired, or teeth, as in the Pacinotti ring, or in fact any IIO other suitable arrangement may be adopted to bring the two elements into magnetic relation. The outer coil 20, as shown, is mounted on posts 26, which are placed upright on a base 27, the coil 2O being secured firmly in place by straps 26, and the whole may be inclosed in a suitable case 39 of cylindrical form with a closed end and secured to the base by fastenings, such as screws 41. The inner coil 21 is fixed on an upright shaft 28 by means of cross-pieces 29. At the lower end of this shaft is formed a pivot 30, which rests on a hardened bearing, such as a jewel 31, supported in a block 32, which slides vertically in a socket 33, formed in the base, and is varied in position by means of a set-screw 34, having a milled head 35 and engaging with a fixed nut 36, secured to the base, by which arrangement the shaft 28, and hence the coil 2l, maybe adjusted in vertical position. The upper end of the shaft passes through a hole 37 in the center of the, coverplate 40 of the casing 39. Just below the cover 40 the shaft 28 is provided with a collar 38, and to the under side of the cover is secured a bearing-block 42, the two pieces 38 and 42 being formed with raceways to receive balls 43 and constituting a ball-bearing. The shaft 28 is readily slidable through the collar 38, so as to permit of ready dismounting of the apparatus. To the upper end of the shaft 28, which projects above the cover 40, is fixed an index finger or pointer 44 or any suitable means for ascertaining the movements of the shaft from the outside,this finger being removably attached by a thumbnut 45, engaging with a threaded stud 46, formed on the end of the shaft 28.

Each of the coils 20 21 is divided into a number of aliquot ports depending on the number of phases of the circuit-as, for instance, into three parts for a three-phase circuit, four parts for a two-phase, and so on,

and leads connected to the coils at these points. These leads 47 for the outer coil are electrically connected with a series of binding posts or terminals 48, while the leads 49 from the inner coil 21 are connected, as shown, to a series of collector-rings 50, these being in the instrument shown in Fig. l three in number, the instrument being for a three-phase circuit. Against the collectorrings 50 press brushes 51, which are supported in brackets 52, electrically connected. by wires 53 to the binding posts or terminals 54. I also prefer to provide a brake for holding the inner coil in a stationary position, eX- cept when desired to indicate. the synchronism of the circuit, this brake being in the form of an angular lever 55, pivoted at 56 in ears 57 to one of the posts 26, and whose horizontal limb is provided with a fork 58, taking under one of the collector-rings 50, and its other or vertical arm 59 projects downwardly and is engaged by the end of a setscrew 60. adjustable in the post 26, so that by screwing in the set-screw the fork 58 is raised until the weight of the shaft 28 is lifted partially or wholly off its bearing 31 and supported by the fork 58.

On the cover-plate 40 of the instrument (which may be inclosed, if desirable) are shown two arrows 61 62, pointing in opposite directions and having, respectively, the

legends Fast and j Slow attached thereto,

so as to indicate that the generator which is being synchronized is either fast or slow relatively to the line or to the other generator or circuit to which it is to be coupled.

Fig. 11 shows diagrammatically how this form of the instrument may be connected in order to synchronize two two-phase generators 63 64, it being understood, of course, that in this case there would be four terminals 48 and 54 and collector-rings 50 instead of three. At 65 is a line-circuit to which the generators are respectively connected by four-pole switches 66 67. The former, as shown, is closed to lead the current from the conductors 68 of the generator 63. The switch 67 is open and in like manner has connected thereto the conductors 69 of the generator 64. The outer coil 2O of the synchronizer is connected to the generator 63 in pressure relation by wires 70, in two of which may be interposed resistances 71. in the ordinary voltmeter fashion, while the inner coil 2]. is similarly connected by pressure-wires 72 to the terminals of the generator 64 with interposed resistances 73.

Suppose now that the two generators are running in perfect synchronism. Each will produce a rotating magnetic field in its coil 20 or 21, and the two fields will rotate at the same speed. Hence there will be no relative rotation induced between the two coils, and the pointer 44 will remain stationary. If, however, the generator 64 running slower than the generator 63, the speed of rotation of the magnetic field in the coil 20 will be less than that in the coil 2'1, and hence the coil 20 will induce a forward (or clockwise) lrotation of the coil 21, and hence the pointer 44 will rotate forwardly. If, however, the generator 64 be running faster than the generator 63, the speed of rotation of the magnetic field in the coil 21 will be greater than that in the coil 20, and in consequence a backward rotation will be induced in the coil 21, and the pointer 44 will rotate backwardly. Hence the direction of rotation of the pointer will indicate to the attendant in charge whether to speed up or slacken his machine to bring it into synchronism, and the machine will be thrown into parallel as soon as the pointer 44 stands stationary, or nearly so. v

Before further describing the different ways of connecting the apparatus I will describe the modifications shown in Figs. 3 to 8, inclusive.

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In Fig. 4 I have shown a modified Form in which the inner ring or coil 21 is replaced by a straight diametral bar 21', as I have 'found it necessary only that one of the two interacting members should have actually a rotating VField, while the other need only carry an alternating lield. Hence Fig. 4 illustrate the substitution of an alternating field for the movable member, the bar 21' being in this case mounted on the shaft 28 and being simply wound with a coil of wire 25', the ends of which are lcd down to collector-rings 50 on the shaft 2S, mounted in thc same manner as the collector-rings 50 and from which the current is taken by means of brushes 51', supported in brackets 52', which are connected to the terminals 54. The other arrangements of this instrument are identical with those in the form shown in Fig. 1, except that I have shown this instrument as provided with a modified form of pointer 44' for side reading, the end 44*l of the pointer being carried beyond and bent over the edge of the cover, where, if desired, it may be read in connection with a scale or arrows on the cylindrical side of the cover instead of from the top.

Figs. 5 and 6 show another modi'tied form of comparative simplicity, which I have used for experimental purposes. In this Vform the outer coil 20, the posts 26, the base 27, and the inner coil 21 are identical in form with these already shown; but herein the shaft 28 is replaced with a stationary pivot-post 2S', fixed in a stationary base-block 74, mounted concentrically on the base 27 and having a pivot at its upper end received by a tubular step 7 5, of glass or otherhard materialnvhichis mounted at the juncture of the two crosspieces 29', which support the coil 2l. In the upper surface of the block 74 are formed concentric grooves 7 6,equal in number to the number of phase of the circuit and herein shown as 'four in number, for a 'four-wire two two-phase connection. In each of these grooves is contained a quantity of mercury 77, and into the mercury depend the wire leads 49 from the coil 21, so as to make electrical contact therewith, while the current is led to the grooves by leads 7 7', passing downwardly through the blocks 74 and outwardly on the base 27 to terminals 54".

It will be seen that the structure is such that the inner coil 21 may freely rotate about its pivot while making continuous contact with the terminals of the circuit by :means o'l" the mercury-troughs 7 6.

In Figs. 7 and S is shown a third moditication embodying the features shown by Figs.

5 and 6 in connection with a straight bar 21', the same as in Fig. 4. In this case the block 74 is replaced by a block 74', having only two grooves 7 6 therein, into which are led the terminals 49' of the coil 25', which is wound in the same manner as the bar instrument, (shown in Fig. 4,) the two mercury-troughs being connected by leads 77' to a pair ol terminals 4S", which are connected to the poles ol an alternating circuit or to the combined poles of a polyphase circuit in a manner which will be presently pointed out.

In Fig. 12 is shown a diagram of connections of a double-ring instrument Afor synchronizing the two-pbase or 'four-phase generator 78 with a line-circuit consisting of lour bus bars or wires 79. The currentwires S0 of the generator arc supposed to be connected to the several bus-bars 79 by a tour-pole switch 81, and this is o'l2 course left open until the generator 7S arrives at the proper speed. Pressure-wires 82, having resistancc S3 interposed in two of them, are led 'from the terminals of the generator to the terminals ol one oi" the two rings, herein shown as of the inner ring or coil 21. of thc synchronizer, while thc terminals ot the outer ring 20 are permanently connected through resistance S4 by pressure-wires S5 with the bus-bars 79, respectively. The synchronizer in this case operates in precisely the saine manner as already described for Fig. 11, the synchronizer-pointer rot ating in one direction or the other until the generator reaches the proper speed, when it comes to a stand, and the switch S1 is cut into circuit.

In Fig. 1.3 is shown the manner ol connecting a series of three-phase generators with a single synchronizer so as to synchronize any of them with the line-circuit. In this 'ligure the line-circuit or bus-bars are designated 79', and one of the two rings or coils of the synchronizer (herein shown as the outer) is connected with the bus-bars 79' bv pressurewires S5', which may contain resistanccs S4'. The terminals of the other coil 21 are likewise connected by pressure-wires 82', having interposed resistances SB', to thc terminals ol" a three-pole change over-switch 86, whose free end may be alternately connected with the respective poles S7 of any one ol: the threophase generators 88 in the station by means of pressure-wire connections i2l. The current-mains 80 from these generators are connected with the bus -bars 79' by triple switches 81', as will bc readily seen, and the generator which is to bc coupled up with the line may be thrown into synchronism therewith by connecting the switch S6 with its pressure-wires 822 Figs. 15 and 16 show the arrangements which may be adopted, respectively, 'for a tour-phase and three-phase circuit, where the inner coil is replaced by a straight bar, as in Figs. 4 and 7. In Fig. 15 the outer coil or ring 2() is connected with the bus-bars 79 in the same manner as in Fig. 12. The lour pressure-wires 82 are, however, replaced by i l two pressure-wires S2" 'trom the ternnnals oi around the bar. This instrument operates I the bar 21 which are connected, through a IOO resistance 83, to a double-pole switch 86, whose free end may be connected to a pair of opposite poles of either of the two generators by means of pressure-wires 82h. 1t will be seen that while the line-circuit produces a rotary field in the ring 2O an alternating field only is produced in the bar 21 by its connection with the generator 78; but this alternating field should be in phase with the rotating field before the generator is thrown into circuit. It is obvious that if the frequency of both the ring and the bar is the same the latter will set itself so that at the time its poles are of maximum strength they will be opposite points on the ring, where the poles are likewise of maximum strength; but if the frequency of the current in the bar is less than in the ring its maximum will occur somewhat later than at this point in the ring, and consequently on each rotation of the field in the ring it will pull the bar through a small angle, depending upon the amount of lag, and thus cause it to rotate continuously in the same direction in the same manner as where there are two rings. Of course in this case the ring 20 must be so wound and connected that its magnetic field shall present opposite poles at opposite extremities of a diameter.

rig. 16 shows the connections of a similar formof synchronizer for athree-phase circuit. In this case the three-pole change-over switch 86 is still employed to connect the bar 21 to the synchronizer, with the pressure-wires 82a from the generator 88; but one of the leads 82 from the bar-coil is connected directly to one of the poles of the three-pole switch 86, while the other lead 82 is connected in the center of a resistance 83", the two ends of which are connected to the other two poles of the switch, as shown. The resistance 88 should be kdouble that of the coil 25 on the bar, so that the actual connection of the three-pole switch 86 is identical w ith the ordinary form of star connection, whereas the coils in liig. 13 and the outer coil in Teig. 16 are shown connected as in delta connection. Of course this is only one of the modes that may be adopted, which is shown by way of illustration.

In lnig. 9 is shown a combination synchronizer and lag-indicator or combination synchronizer and power-factor incic ator and in if ig. 14 the manner of connecting the same. This instrument embodies the features of my improved lag-indicator or power-factorincicator, an application for which I have filed simultaneously herewith and which l do not claim separately in this application. This instrument is adapted to innicate either the relative phase of two circuits, the lag of the current in one of them, or the power factor, as ma be desired. The instrument is identical w ith that already described, except that the pointer 44 is provided with a scale 88 of about one hundred and eighty degrees, on which are marked graduations 89 on the inner side, indicating the angle from the Zero or central point of the scale, and on the outer side graduations 90, which are in proportion to the cosine of the angle and represent the power factor, the central point being numbered 1 on this scale. The scale must be so placed that the pointer shall come to rest at the zero or central point of the scale when the generator and line are in synchronism and phase and when the instrument is acting as a synclironizer, and the manner of the operation of this instrument will be exhibitedY from the connections shown in Fig. 14. 1n this diagram, which is shown for a threephase circuit for convenience, the outer coil 20 is provided in addition to the terminals 48, which are connected with three points at distances of one hundred and twenty degrees on A the ring, with three other terminals 91 at distances of sixty degrees from the terminals 48. The three terminals 48 are, as previously arranged, connected with the respective bus-bars 79, but in this case by heavy leads 92, while the three terminals 91 are connected by heavy leads 98 with the mains 808 of the generator 88 through the threepole switch 81. The terminals 54 of the inner coil are connected by the pressure-leads 82 with the respective poles of the generator, as previously. Now when it is desired to throw the generator into synchronism the switch 81 is open, and in this case the two coils 20 and 21 are connected up in precisely the same manner as heretofore described for Fig. 18-that is to say, in voltage relation to the generator and line-circuit, respectivelyso that the inner coil 21 will rotate continuously in one direction or the other until the two circuits are in phase. /Vhen this happens, the switch 81 is cut in, and the instrument will now act as a lag-indicator, because the current through the mains 80 will flow through the leads 93, through the coil 2O and IOC .lIO

the leads 92 to the bus-bars, while the inner coil will receive a rotating field, due to the voltage of the generator, in the same manner as before. `While the frequency of the two circuits is the saine, one of these circuitsin general, the current-circuit-will either lag behind or lead the other. Hence the pointer instead of oo ming to rest at the zeropoint, as shown in Fig. 9, will come to rest at an angle at one side thereof, depending upon the angle of lag or lead of the circuit, and will thus indicate the angle of lag and power factor upon the scale. In this case it might be found necessary to wind the outer ring with two independent coils for current and pressure, respectively, as will be readily understood.

Fig. 10 shows a view of a side-reading instrument for switchboard use, in which the scale for indicating the lag and lead (designated 88') is formed on the electrical side of the instrument on a card which may be placed Within a glass panel 94, the end of the pointer 44 being brought down, as at 44h, to this scale in the same manner as in if ig. 4 except that the pointer is Within the cover of the instrument.

As will be readily understood, var'ious modifications of my improved synchronizer and combined synch'onizer and lag-indicator may be devised, those lrerein snonn by me being merely by Way of illustration of forms in which it may be embodied, and I desir'e it to be understood that my present invention embraces all such modiiications and mechanical and electrical equivalents so far as tney lie within the scope of the lol lowing claims.

Having thus described my invention, 'what I claim as new, and desire to secure by Letters Patent, is-

l. A synchronizer comprising a nragnetic ring Wound to produce a rotating iield, a magnetic bar mounted in tire plaire of and concentrically n ith said ring and having also magnetic n indings, and means for connecting said ring and bar respectively to ti.e two currents to be synchronized.

2. A sync'rrronizer conrprising a magnetic ring Yhaving innings adapted to produce a rotating iield and mounted in a horizontal plane, a revoluble magnetic member 'having magnetic windings and mounted to turn coaXially ith said ring on a vertical spindle, and means for connecting tl.e n indings of said ring and member respectively a ith ti.e currents to be synchronized, said means conrprising in the case of tie revoluble member annular nrercuryecups into \\'l-ich tl-e termi nals of tire windings of said member continuously dip thus permitting 'free rotation ol' said member.

3. A synchronizer comprising a base, an iron ring-core mounted thereon, a polyprase Winding on said core, a concentrically-mounted rotatable shaft, a magnetic core concentrically mounted on said shaft and coacting with said ring, a n inding covering said mage netic core, a collar on said sirait and tl.rough which said shaft is slidable, a bearing vfor said collar, means for electrically connecting the winding on said magnetic core in pressure relation n ith a current to be synclrronized, and a brake acting on said shai't and operated from tire side oi tie instrument.

4. A synchronizer comprising a stationary magnetic member having n indings adapted to produce a varying field, a revoluble irragnetic member also having windings and mounted in a horizontal plane, tlre n indings of one of said members being adapted to pr'oduce a rotating ield, a spindle on Which said second nrember turns, and an adjustable step for said spindle enabling the raising or lo ering oi' said second member with respect to the iirst.

5. A synchronizer comprising a stationary magnetic member having windings adapted to produce a varying iield, a revoluble irragnetic member also having nindings and mounted in a horizontal plane, tire nindings of one oi said members being adapted to pr'oduce a rotating lield, a spindle on n Lich said second member turns, and a lever-brake acting from beneath said second member' and tending to raise tie same lrom its bearing.

6. A sync'nr'onizer comprising a stationary magnetic member' having n innings adapted to produce a varying ield, a revoluble irragnetic member' also lraving n indings and mounted in a horizontal plane, tie nmdings of one ol" said members being adapted to produce a rotating iield, a spindle on Lich said second member turns, a brake-disk revolv ing u ith said second member', a lever-brake under said eisk, and means i'or pressing said brake against said disk.

7. A synclrronizer comprising a stationary magnetic member Laying windings adapted to produce a varying held, a revoluble magnetic member also lraving n indings and mounted in a horizontal plaire, tlrc n indings of one of said members being adapted to produce a rotating lield, a spindle on Iiclr said second menrb er turns, a brakedisk revolving n ith said second member', a lever-brake under' said disk, and a laterally-projecting screw acting on said brake to press it against said disk.

8. A combination synclgronizer and lag-indicator, comprising a stationary annular' electromagnetic member' laving a inning of electric conductors, an alternating cir'cuit connected in pressure relation to said membei', a second electromagnetic member concentrically mounted to rotate adjacent to tie iirst, a generator-circuit, pressure-n ir'es connecting tie poles of said generator-circuit n ith 4said second electromagnetic member', a pointer carr'ied by said second member and rotating tieren ith, a scale mounted adaeent to said pointer and having tie angle of lead and lag marked tlereon, and means lior changing tire connection oi'l said stationary member, whereby it is connected in current relation to said generator.

In testimony wlrereoi: I have lzereunto subscribed myhand tlris 11th day of June, 1903.

WILLIAM II. FREEDMA.

I/Vitnesses F. W. Wni'roorrn, B. B. BALDWIN.

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